1. Field of the Invention
This invention relates to a refrigeration system with a centrifugal economiser.
2. Description of the Prior Art
French Patent No. 2.541.437 discloses a centrifugal economiser for a refrigeration or the like (heat pump, etc.) system.
As is well known, in a circuit comprising an economiser, part of the gas produced by the expansion valve is returned to the compressor at a pressure intermediate between the intake and discharge pressures, thereby to increase by the same amount the quantity of "useful" gas taken in by the compressor and to improve its capacity as well as its thermodynamic efficiency.
In the abovementioned patent separation of the liquid sent to the evaporator from the gas going towards the economiser orifice is performed by a rotor, rotating in a stationary casing. The gas exits generally near the axis of rotation of the rotor and the liquid at the periphery ; appropriate means ensure that no gas leaves with the liquid, so as to fully enjoy the advantages of the device. This is obtained by controlling the liquid flow by a valve, which opens and closes as a function of the thickness of the liquid ring continuously formed around the rotor.
It has nevertheless been noticed that this device has drawbacks. First, though simple, said valve costs a certain amount. But moreover, if for any reason, say a chip, the valve jams, the centrifugal separator no longer operates : either the valve is too open, and a major part of the gas goes to the evaporator, or it remained too closed whereby a great portion of the produced liquid is sent uselessly to the compressor.